1. Field of the Invention
The present invention relates to a video printer device, and more specifically to an improved video printer device for printing a video signal corresponding to an arbitrary scene from a continuous video signal such as a television signal, etc., or printing a video signal from a still video camera.
2. Description of the Prior Art
A television is now widely accepted as an apparatus to provide a picture (moving picture) operative on the basis of a continuous video signal. In such a television system, a screen changes at 30 frames/sec, for example, to provide a moving image at which observers look as a changing picture.
It is earnestly needed to obtain a still image of a desired scene from the television image, and there are accordingly devised varieties of techniques such as that for printing up to now, and practically used. Also, in general domestic applications, there are existent similar demands for which a video printer is available which prints out a still image from a video signal in a television system and a video system with use of a printer.
In such prior video printers, a video signal is printed out intactly without any correction thereof. Therefore, a high quality input video signal, if inputted, assures a high quality print out image. However, video signals in television systems and video signals recorded in video recorders are difficult in manifesting good image quality as will be described below, and hence the prior video printers suffer from a difficulty that they fail to afford a high quality print out image.
More specifically, out of the reasons why the aforementioned video signal has bad image quality lies in itself. It is common for a video signal displayed on a television that a picture changes continuously at the rate of 30 frames/sec to provide an animation as described previously. Even if a picture of each frame is deteriorated in quality owing to any existent noise and the like, successive pictures are averaged to compensate for the deteriorated pictures quality. However, when a picture which changes every 1/30 sec is printed out as a still picture, the noise is outstanding, resulting in bad picture quality.
The other reason is that the picture image displayed on a display based on the video signal does not match the picture image printed out on a printer owing to differences therebetween concerning various factors such as coloring principles, and reproduced ranges and tones. In a photographic process, even if a highlight and a shadow are somewhat improper in view of exposure conditions upon photographing, proper exposure can be achieved by adjusting the exposure during development and printing. However, in the prior video printers, a picture image is printed out directly from a video signal and hence any picture image with desired quality can not be yielded because of mismatching of the ranges as described above and the like.
However, the present status of technical innovation and high technology has outstandingly improved image qualities in televisions and video recorders, and the fine structure of a picture image is also satisfactory in itself. It is therefore earnestly desired to print out a high quality picture image. However, the prior general video printers do not include means to refine image quality and allow a bad input signal to be transmitted to an output without producing a good quality still picture image printed.
Furthermore, in the prior printers, although a picture image can be changed in the light and shade, and colortone thereof and outputted after being stored, such a picture image can not be checked and adjusted on real time and the adequacy of the adjustment can be manifested only after a picture image is printed out.